JP2010069160A - Racket for sound table tennis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a racket for sound table tennis (STT) which allows an angle to be objectively determined without relaying on a visual inspection. <P>SOLUTION: The racket 10 includes a racket body 12A and a shaft 14. The shaft 14 internally stores a circuit board 18 and a power source 26. An LED 28 for emitting green light and an LED 30 for emitting red light are arranged at an edge at the front end of the racket body 12. The circuit board 18 has a gyro sensor, an acceleration sensor, and a microcomputer. The LEDs 28, 30 are connected to the microcomputer. The microcomputer calculates the inclination angle θ of a ball hitting surface 12A with respect to a table tennis table 16, based on the detection signals of the gyro sensor and the acceleration sensor, turns on the LED 28 when the result is equal to or more than a prescribed angle, and turns on the other LED 30 when the result is less than the prescribed angle. Consequently, the inclination angle θ of the racket 10 is objectively determined. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a racket for sound table tennis (STT).

  In recent years, disabled sports are not only a part of rehabilitation (function recovery training), but also promote the health of disabled people, encourage social participation, promote understanding of disabled people and disabled people, and enjoy sports. The social recognition has increased and it has become widespread. However, it is also true that there are various problems due to being disabled in competitions. Currently, in order to reduce the influence as much as possible, the rules for making sports unique to disabled people are made, and the competition equipment is improved.

  For example, table tennis for visually impaired people called sound table tennis (hereinafter referred to as STT) is a sport that can be enjoyed easily by visually impaired people, such as schools for the blind and nationwide tournaments. . STT is a ball that rolls under the net using a ball containing a metal ball and a wooden racket without rubber. Sound is the most important factor in the competition. Sound is one of them. The determination of the hitting sound is performed based on whether the angle formed by the racket hitting surface and the ping-pong table when hitting the ball is 60 degrees or more in addition to the “sound” itself.

  However, the determination of the angle described above currently depends on a sensuous method of visual inspection by the referee, and how to accurately determine the angle is an issue in the competition.

  The present invention focuses on the above points, and an object of the present invention is to provide a sound table tennis (STT) racket capable of performing objective angle determination without relying on visual observation.

  In order to achieve the above object, the present invention is a racket for sound table tennis, and is characterized by comprising an inclination angle detecting means for detecting an inclination angle of a hitting surface of the racket with respect to a table tennis table. Another invention is a racket for sound table tennis, which is a gyro sensor that detects an angular velocity with the axis of the racket handle as the rotation axis, and an acceleration sensor that detects the acceleration of the racket in the biaxial direction perpendicular to the rotation axis The tilt angle of the racket striking surface with respect to the ping-pong table is calculated from notifying means for notifying whether the inclination angle of the racket striking surface with respect to the table tennis table is equal to or larger than a predetermined angle, the detection signal of the gyro sensor and the acceleration sensor And an arithmetic processing means for driving the notifying means according to a calculation result, the gyro sensor, an acceleration sensor, an informing means, and a power source for supplying power to the arithmetic processing means.

  One of the main forms is characterized in that the notification means notifies whether or not the hitting surface of the racket is equal to or larger than a predetermined angle by at least one of light, sound, and vibration. Another embodiment is characterized in that the gyro sensor, acceleration sensor, arithmetic processing means, and power source are incorporated in the handle of the racket. Yet another embodiment is characterized in that the notification means is provided at an edge of the racket body.

  Still another embodiment is provided with a hitting ball detecting means for detecting a hit ball by the hitting surface of the racket, and the arithmetic processing means drives the notification means when the hit ball is detected by the hit ball detecting means. It is characterized by. In still another aspect, the hitting ball detecting means detects an impact at the time of hitting with a piezoelectric sheet provided on the hitting surface, or detects vibration at the time of hitting using the acceleration sensor. And

  Still another embodiment is provided with ball detecting means for detecting that a ball to be hit is within a predetermined distance, and the arithmetic processing means is configured to detect when the approach of the ball is detected by the ball detecting means. The informing means is driven. Yet another embodiment is characterized in that the ball detecting means is a magnetic sensor and detects magnetism generated from a magnet provided in the ball. The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

  The present invention incorporates a gyro sensor and an acceleration sensor into a rack for sound table tennis, and calculates from the detection signals of these sensors whether or not the inclination angle of the hitting surface of the racket with respect to the ping-pong table is equal to or greater than a predetermined angle. And since the result was notified by an alerting | reporting means, the effect that objective angle determination is attained is acquired.

  Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples.

  First, Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1A is an external perspective view showing a use state of the present embodiment, and FIGS. 1B and 1C are front views of the above-described (A) as viewed from the front end side of the racket. FIG. 2A is a diagram showing a circuit board of this embodiment, and FIG. 2B is a plan view showing the internal structure of the racket. FIG. 3 is a flowchart showing an angle determination processing procedure according to the present embodiment. The racket 10 for sound table tennis (STT) of the present invention has a function of detecting the inclination angle of the hitting surface with respect to the table tennis table.

  As shown in FIGS. 1A and 2B, the racket 10 includes a racket body 12 and a handle 14. The handle 14 is hollow, and a circuit board 18 having an angle determination function and a power source 26 are accommodated inside thereof, and is covered with a removable cover 14A. Further, LEDs 28 and 30 are provided at the edge of the racket body 12 on the front end side (the side opposite to the handle 14). The LEDs 28 and 30 emit light in different colors, thereby notifying the referee or the like whether the inclination angle θ of the hitting surface 12A of the racket body 12 with respect to the table tennis table 16 is equal to or greater than a predetermined angle. In this embodiment, the green LED 28 is turned on when the inclination angle θ is 60 degrees or more, and the red LED 30 is turned on when the inclination angle θ is less than 60 degrees.

  2A, the circuit board 18 includes a gyro sensor 20 that detects an angular velocity of the racket 10, an acceleration sensor 22 that detects an acceleration of the racket 10, and the gyro sensor 20 and the acceleration sensor 22. It is comprised by the arithmetic processing unit connected to. The gyro sensor 20 detects an angular velocity (see an arrow F1 in FIG. 1B) whose axis of rotation is the axis of the handle 14 of the racket 10, that is, the y axis in FIG. The sensor 22 detects accelerations in two axes orthogonal to the rotation axis, that is, the x-axis and y-axis directions in FIG. In the present embodiment, the microcomputer 24 is used as the arithmetic processing unit for embedding in the racket 10. Such a circuit board 18 is housed inside the handle 14 together with the power source 26 and receives power from the power source 26. Further, the microcomputer 24 is connected to the LEDs 28 and 30 by wiring provided inside the racket body 12. Then, a lighting instruction is sent to either the LED 28 or the LED 30 according to the tilt angle θ calculated from the detection signals of the gyro sensor 20 and the acceleration sensor 22. The power supply from the power supply 26 can be switched ON / OFF by a switch 27 provided at the end of the handle 14, for example.

The inclination angle θ of the hitting surface 12A is calculated as follows. When the output signal from the acceleration sensor 22 is combined into a low-pass filter and the integrated output signal from the gyro sensor 20 is combined into a high-pass filter, the inclination angle θ is expressed by Equation 1 below. Here, T is a time constant and T = 2πf ₀ (f ₀ : cut-off frequency).

From Equation 1, the following Equation 2 is obtained.

Next, Equation 2 is discretized to obtain Equation 3 below.

In Equation 3, when ω = 1 / T, the following Equation 4 is obtained.

  Therefore, by programming Equation 4 in the microcomputer 24, the tilt angle θ can be calculated from the output signals of the gyro sensor 20 and the acceleration sensor 22 collected every sampling time. In addition, although the inclination angle θ in Equations 1 to 4 described above strictly represents the inclination angle with respect to the horizontal plane, the table tennis table 16 is actually installed so that the surface is substantially horizontal. The inclination angle θ may be considered as an inclination angle with respect to the table tennis table 16.

As described above, when the inclination angle θ is calculated by combining the gyro sensor 20 and the acceleration sensor 22, an error occurs depending on the value of f ₀ , so the measurement error due to the change of f ₀ was verified. An angle detection program for calculating the tilt angle θ is constructed on the PC based on the mathematical formula 4, the output signals of the gyro sensor 20 and the acceleration sensor 22 are fetched on the PC, the calculation is performed, and the tilt angle is calculated by the rotary potentiometer. The measured values were measured, and the measured values were compared with the calculated values for the same movement. The experiment is performed when the value of f ₀ is 0.01 Hz, 0, 1 Hz, 1 Hz, and 10 Hz. The rotational motion characteristics, the rotation + vibration (horizontal) motion characteristics, and the startup characteristics (characteristics when the power is turned on) The following three characteristics were verified.

As a result, proper values of f ₀ was found to be 1Hz vicinity. Therefore, in order to verify the value of f ₀ more finely, when f ₀ is 0.7 Hz, 0.8 Hz, 0.9 Hz, and 1 Hz, a similar experiment was performed. As a result, f ₀ was 0.7 Hz to 1 Hz. between the difference in inclination angle θ due to the difference in the value of f ₀ it was hardly observed. Thus, the appropriate value of _{f 0} was found to be in the range of 0.7～1Hz.

Next, an evaluation test of the racket 10 of this example was performed. Two types of the racket 10 were prepared, with f ₀ set to 0.7 Hz and 1 Hz. The evaluation was performed 10 times each for the hitting method when the angle θ formed by the racket striking surface 12A and the table tennis table 16 is 60 degrees or more (OK) and less than 60 degrees (NG) in the actual competition environment. Table 1 For _f 0 = 0.7 Hz, Table 2 shows the results when the _f 0 = 1 Hz.

From Table 1 and Table 2, setting the _{f 0} to 1 Hz, the percentage of correct determination was found to be 100%. Note that when setting the f ₀ is 0.7 Hz, the correct answer rate in the case of less than 60 degrees does not reach 100%, a tendency that the response speed is slow with respect to a change in higher tilt angle θ value of f ₀ is smaller For this reason, it is considered that the determination was made erroneously without being able to respond to the movement of the racket 10.

  Next, the operation of this embodiment will be described with reference to FIG. First, in a state where the switch 27 is turned on and the power source 26 is turned on (Yes in step S10), the gyro sensor 20 detects the angular velocity and the acceleration sensor 22 detects the acceleration (step S12). These detection signals are sent to the microcomputer 24, and the inclination angle θ of the racket 10 is calculated based on the above-described equation 4 (step S14). When the inclination angle θ of the racket striking surface 12A with respect to the table tennis table 16 is 60 degrees or more (Yes in step S16), the microcomputer 24 sends a lighting instruction to the LED 28, as shown in FIG. The green LED 28 is turned on (steps S18 and S20). On the other hand, when the tilt angle θ is less than 60 degrees (No in step S16), the microcomputer 24 sends a lighting instruction to the LED 30, and the red LED 30 is lit as shown in FIG. Steps S24 and S26).

  The operations in steps S12 to S26 are repeated until the power supply 26 is turned off (No in step S28), and are terminated when the power supply 26 is turned off (Yes in step S28). Thus, since the LED 28 or the LED 30 is always lit according to the inclination angle θ while the power supply 26 is turned on, the referee of the competition determines the angle when the ball 40 hits the racket 10. It can be easily determined from the lighting of the LED 28 or the LED 30.

  As described above, according to the first embodiment, the handle 14 of the STT racket 10 includes the gyro sensor 20 and the acceleration sensor 22, and the inclination angle of the racket striking surface 12 </ b> A with respect to the table tennis table 16 from the detection signals of these sensors. The microcomputer 24 calculates whether θ is equal to or greater than a predetermined angle. And since the result was notified by lighting of LED28 or LED30, there exists an effect that objective angle determination becomes possible.

In addition, this invention is not limited to the Example mentioned above, A various change can be added in the range which does not deviate from the summary of this invention. For example, the following are also included.
(1) In the above-described embodiment, it is determined whether the inclination angle θ is 60 degrees or more by switching the lighting of the LED 28 that emits green light and the LED 30 that emits red light. However, this is an example. You may make it use LED which light-emits a color. In addition, it is not always necessary to prepare two-color LEDs, and one LED may be turned on when the inclination angle θ is 60 degrees or more and turned off when the inclination angle θ is less than 60 degrees. Of course, the reverse is also possible.

  (2) In the above embodiment, the LEDs 28 and 30 are provided at the edge on the front end side of the racket body 12, but it may be provided at several places on the edge of the racket body 12 or at the entire edge. The handle 14 may be provided. Alternatively, a part or the whole of the racket 10 may be covered with a transparent acrylic plate or the like, and the covered portion may be caused to emit light by an LED provided on the inside thereof.

  (3) In the above embodiment, whether or not the inclination angle θ is greater than or equal to a predetermined angle is notified by lighting the LEDs 28 and 30, but this is an example suitable for a game with a referee and has the same effect. If it is a thing, you may utilize other well-known various alerting | reporting means. For example, it is convenient for practice because the player (visually impaired person) can confirm the inclination angle by notifying the angle determination result with sound like a buzzer. Needless to say, a combination of light and sound may be used for notification, and in that case, a means capable of switching to only light, only sound, or a combination of light and sound may be provided. Vibration may be used as a notification means.

  (4) In the above-described embodiment, the LED 28 or the LED 30 is always lit while the power supply 26 is turned on. However, notification by light or sound may be performed only when a ball is hit. For example, as shown in FIG. 4 (A), the racket striking surface 12A is covered with a piezoelectric sheet 50 as a hitting ball detecting means, and the LED 28 or the LED 30 is turned on when an impact at the time of hitting is detected with the piezoelectric sheet 50. Condition. Also, the hitting ball detecting means is not limited to the piezoelectric sheet 50, and the same effect can be obtained, for example, by using the acceleration sensor 22 to determine the presence or absence of a hit ball from the change in acceleration at the time of hitting. For example, various known hitting ball detection means can be used.

  (5) Alternatively, the LEDs 28 and 30 may be lit when the ball 40 approaches within a predetermined distance from the ball striking surface 12. For example, as shown in FIG. 4B, a ball 40 for sound table tennis contains a metal ball 42 for producing a sound, but a magnet 44 is put together with the metal ball 42 so that the racket 10 By incorporating the magnetic sensor 52, the magnetism generated from the magnet 44 can be detected. When the magnetic sensor 52 detects that the ball 40 has approached within a predetermined distance, it notifies whether or not the inclination angle θ is equal to or greater than a predetermined angle by any of the methods described above. Of course, the ball detecting means shown in FIG. 4B is also an example, and the design may be changed as appropriate so as to achieve the same effect.

  (6) As in the example shown in FIG. 4 (C), the power source built in the handle 14 of the racket 10 is a rechargeable battery 54, and terminals 56A and 56B are provided on the handle 14 and set on the charging stand 58. It may be in a form that can be charged.

  (7) In the above embodiment, the lighting of the LEDs 28 and 30 is switched depending on whether the angle θ formed by the ball striking face 12A and the table tennis table 16 is 60 degrees or more, but less than 60 degrees. It may be set to an angle other than 60 degrees.

(8) In the above embodiment, the optimum value of the cut-off frequency f ₀ is on average around 1 Hz. However, since there are individual differences in how to hit the racket, the cut-off frequency is set to the optimum value depending on how to hit. An adjustment function for adjustment may be provided. Furthermore, a learning function for adjusting the optimum value based on the adjustment history may be provided.

  According to the present invention, the gyro sensor and the acceleration sensor are incorporated in the racket, and the calculation processing means calculates whether the inclination angle of the racket striking surface with respect to the table tennis table is equal to or greater than a predetermined angle from the detection signals of these sensors. By notifying the result by the notification means, an objective angle determination becomes possible, and therefore, it can be applied to the use of a racket for sound table tennis.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Example 1 of this invention, (A) is the external appearance perspective view which shows a use condition, (B) And (C) is the front view which looked at the said (A) from the racket front end side. It is a figure which shows the said Example 1, (A) is a figure which shows a circuit board, (B) is a top view which shows the internal structure of a racket. It is a flowchart which shows the angle determination processing procedure of the said Example 1. FIG. It is a figure which shows the other Example of this invention.

Explanation of symbols

10: Racket 12: Racket body 12A: Hitting surface 14: Handle 14A: Cover 16: Ping-pong table 18: Circuit board 20: Gyro sensor 22: Acceleration sensor 24: Microcomputer 26: Power supply 27: Switch 28: LED (green)
30: LED (red)
40: Ball 42: Metal sphere 44: Magnet 50: Piezoelectric sheet 52: Magnetic sensor 54: Battery 56A, 56B: Terminal 58: Charging stand

Claims (10)

A racket for sound table tennis,
Inclination angle detection means for detecting the inclination angle of the hitting surface of the racket with respect to the table tennis table,
Sound table tennis racket characterized by having. A racket for sound table tennis,
A gyro sensor that detects the angular velocity about the axis of the racket handle,
An acceleration sensor for detecting acceleration of a racket in a biaxial direction perpendicular to the rotation axis;
Informing means for informing whether or not an inclination angle of the hitting surface of the racket with respect to the table tennis table is equal to or larger than a predetermined angle;
An arithmetic processing means for calculating an inclination angle of a hitting surface of the racket with respect to the table tennis table from detection signals of the gyro sensor and the acceleration sensor, and driving the notifying means according to the calculation result;
A power supply for supplying power to the gyro sensor, acceleration sensor, notification means, and arithmetic processing means;
Sound table tennis racket characterized by having.   3. The sound table tennis racket according to claim 2, wherein the notification means notifies whether or not the hitting surface of the racket is equal to or larger than a predetermined angle by at least one of light, sound, and vibration.   4. The sound table tennis racket according to claim 2, wherein the gyro sensor, acceleration sensor, arithmetic processing means, and power source are built in the handle of the racket.   The sound table tennis racket according to any one of claims 2 to 4, wherein the notification means is provided at an edge of a racket body. Hitting ball detecting means for detecting a hitting ball by the hitting surface of the racket,
And providing
6. The sound table tennis racket according to claim 2, wherein the arithmetic processing means drives the notifying means when a hit ball is detected by the hit ball detecting means.   7. The sound table tennis racket according to claim 6, wherein the hitting ball detecting means detects an impact at the time of hitting with a piezoelectric sheet provided on the hitting ball surface.   The sound table tennis racket according to claim 6, wherein the hitting ball detecting means detects vibration at the time of hitting using the acceleration sensor. Ball detecting means for detecting that the ball to be hit is within a predetermined distance;
And providing
6. The sound table tennis racket according to claim 2, wherein the arithmetic processing means drives the notifying means when the approach of the ball is detected by the ball detecting means. The ball detection means is a magnetic sensor,
The sound table tennis racket according to claim 9, wherein magnetism generated from a magnet provided in the ball is detected.

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